JPS63205352A - Polyamide composition and molded product thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to mixtures of 30 to 95% by weight poly(hexamethylene isophthalamide) and 5 to 70% by weight poly(hexamethylene adipamide) and molded articles of these mixtures. be.

Such mixtures have improved processing properties, such as good flow properties of the melt and high elongation at break of the molded products.

It has long been known that mixtures of partially crystalline and non-crystalline polyamides have better properties in certain respects than the starting polyamide. According to European Patent No. 70.001, the resistance of partially crystalline polyamides to chemicals, in particular to zinc chloride solutions, has been shown to be excellent against isophthalic acid, terephthalic acid, hexamethylene diamine and 4,4'-diaminodicyclohexyl. It can be improved by adding certain copolymers of methane. However, this method does not produce any significant improvement in mechanical properties.

According to German Patent Application No. 1,769,040, a partially crystalline polyamide and terephthalic acid and 2.
2.4- and 2,4.4-) Dimethylhexamethylenediamine isomer mixtures of non-grade polyamides give rise to molded articles with high notched impact values and a tendency to low shrinkage, but the mixtures The toughness is intermediate to that of the starting material and is not significantly improved.

surface defects found in partially crystalline polyamides reinforced with glass fibers or containing fillers, as disclosed in German Patent Application No. 3,200,428;
Defects that occur especially near the sprue are
This can be prevented by adding 20% by weight of non-grade polyamide. The mechanical properties of polyamides modified by these methods remain largely unchanged.

Surprisingly, the mixture preferably contains 50 to 90% by weight of poly(hexamethylene isophthalamide) and 10 to 5% by weight of poly(hexamethylene isophthalamide).
When comprised of 0 wt. was found to be improved. Mixtures containing polyamide-6 instead of polyamide-66 or other non-grade polyamides such as isophthalic acid, 4,4'-diamino-3,3
Mixtures containing polyamides of '-dimethyl-dicyclohexylmethane and lauryllactam do not exhibit this behavior.

=3- Polyamide-66 and terephthalic acid and 2°2.4-
and a polyamide of an isomer mixture of 2,4,4-trimethylhexamethylene diamine or ε-caprolactam,
A copolyamide of isophthalic acid and isophorone diamine has an elongation at break comparable to a mixture of polyamide-66 and poly(hexamethylene isophthalamide), but
The relatively short flow length of the mixture makes it difficult to process these products into complex molded parts.

Therefore, the present invention provides 30 to 95% by weight, preferably 50 to 9% by weight.
It concerns a mixture of 0% by weight of poly(hexamethylene isophthalamide) and 5-70% by weight, preferably 10-50% by weight of polyamide-66.

2 in Ubbe viscometer
The relative viscosity of the polyamide used, measured on a 1% by weight solution in m-cresol at 5°C, was that of polyamide-66.
2.3 to 4.0, preferably 2°8 to 3.5
, and for poly(hexamethylene isophthalamide) from 1.8 to 3.5, preferably from 2.2 to 2.9. The invention also relates to the use of the mixtures according to the invention for the production of shaped articles by processing the melt.

Compared to known polyamide mixtures, the products according to the invention are distinguished by a combination of properties not found in mixtures of other polyamides. Particularly noteworthy is the improved elongation at break obtained without loss of stiffness or ease of processing. The mixture is permanently transparent if the proportion of polyamide-66 does not exceed 35% by weight. At the same time, the mixtures according to the invention have advantageous flow properties in the melt state ("flow length") and can be processed from the melt to produce molded articles with increased elongation at break.

The products according to the invention are produced by mixing the components in the melt, e.g. by introducing the mixture of polyamide particles into an injection molding machine and processing the melt directly, optionally after mechanical shearing, to produce molded parts. Manufacture. It is also possible to melt the individual polyamides either separately or together and to combine the melts in suitable commercial equipment, such as a double shaft extruder, preferably in a mixing and kneading zone. and the particles produced from this mixture can be processed into molded parts in a known manner.

When formulating the ingredients, customary additives and auxiliaries such as lubricants and release agents, nucleating agents, stabilizers, flame retardants and fillers may be added. Suitable fillers include glass microbeads, chalk, various types of quartz such as Tuberculite (N
vacculites), silicates such as asbestos, feldspar, mica, talc or wollastonite and kaolin in calcined or uncalcined state. Glass fibers may also be added only in limited amounts, generally up to 10% by weight, preferably up to 5% by weight. Mixtures without glass fibers are preferred. Dyes and pigments and impact modifiers such as those based on copolymers of ethylene may also be used, for example on the basis of polybutadiene or poly(meth)acrylates.

Impact modifiers of this type are known, for example, from German Patent Application No. 2,622.973, European Patent No. 1,2
No. 45 and No. 83,446.

Polyamide mixtures are easily processed in conventional injection molding machines and extruders and used in molded products such as injection molded parts, plates, molded parts for the production of machines and technical equipment and in the automotive and electronic industries. parts, as well as products for everyday use, such as eyeglass frames.

EXAMPLES Test samples were produced from a mixture of polyamide particles in an injection molding machine of type Arburg-E at a particle temperature of 280° C. and a machine temperature of 50° C. and the properties of shoulder rods were determined. number 3; thickness 3.2].

The following polyamide was used: A poly(hexamethylene isophthalamide) ηrel=2.4B
Polyamide-66ηrel=3.0C polyamide-6 (
For comparative tests) ηrel=2.9D Copolyamide of ε-caprolactam, isophthalic acid and isophorone (for comparative tests) ηre+=3.8E
Polyamide of terephthalic acid and isomer mixture of 2.2.4- and 2.4.4-1-limethyl-hexamethylenediamine (for comparative tests) -ηrel=2.7F Lauryllactam, isophthalic acid and 3.3'- Dimethyl-4,4'-diamino-dicyclohexylmethane copolyamide (for comparative testing) y+tel=2.5
wood r) rel = relative viscosity measured in m-cresol (solution/25°C).

The composition of the mixture and the properties of the mixture are shown in Tables 1 and 2 below.

Composition (% by weight) of the soybean mixture Properties of the soybean mixture Examples Characteristics Unit of measurement Standard test (
DIN) Tensile strength at break MPa
53455 Elongation at break %
53455 Tensile-E Modulus
MPa, 53457 Piece Softening Temperature V
ST/B'0 53460 Flow length cm The following example shows how the properties depend on the ratio of polyamide-6/poly(hexamethylene sophthalamide) in the mixture.

Cold J Groove Composition of the mixture (% by weight) Measurement of flow length of polyamide mixtures (see Table 4).

In order to measure the flowability of polyamide mixtures, a spirule was taken from a commercial injection molding machine (Arburg).
a+) was extruded. The cross section of the strand (5 strands) that produced the spiral shape was 8 mm in width and 2 mm in height. The temperature measured on the polyamide was 280°C and the temperature of the mold was 50°C.

The injection pressure was 1100kp. Immediately after the flow length became steady, the lengths of the five spiral objects were measured. The values shown are the average values of these measurements.

Numbers represent Examples 1-5.

The flow length measurements in Examples 7.12 and 13 were carried out on a helical wire with a semicircular cross section of width 3.5 mm and height 2.5 mm.

Material temperature: 280℃, mold temperature = 55℃ 0 injection pressure crab 1150kp070-length, Example 7: 36-40cm
, Comparative Example 12: 26-27cm, Comparative Example 13, Near 2-75cm
) Tensile strength at break MPa 534
55 Elongation at break % 53455
Tensile-E modulus MPa 5345
7 flow length cm special order

Claims (1)

Claims: 1. A composition comprising 30-95% by weight of poly(hexamethylene isophthalamide) and 5-70% by weight of poly(hexamethylene adipamide). 2. The composition according to claim 1, comprising 50 to 90% by weight of poly(hexamethylene isophthalamide) and 10 to 50% by weight of poly(hexamethylene adipamide). 3. A composition according to claim 1 or 2, comprising up to 10% by weight of glass fibers. 4. A composition according to claim 3, comprising up to 4.5% by weight of glass fibers. 5, poly(hexamethylene isophthalamide) with a relative viscosity (ηrel) of 1.8 to 3.5 and 2.3 to 4
．． Relative viscosity of 0 (2% in m-cresol solution by weight)
5. A composition according to any one of claims 1 to 4, comprising poly(hexamethylene adipamide) having a poly(hexamethylene adipamide) having a temperature of 5° C.). 6, poly(hexamethylene isophthalamide) having a relative viscosity of 2.2 to 2.9 and poly(hexamethylene adipamide) having a relative viscosity of 2.8 to 3.5. Composition according to item 5. 7. Composition according to any of claims 1 to 6, consisting of one or more customary additives and/or auxiliaries. 8. Use of the composition according to any of claims 1 to 7 for the production of molded articles by processing the melt.